Conventionally, as one of the means for attaching an intended object to the surface of an object, a method of fastening an intended object to the surface of the object is used, including fixing a male surface fastener with hook-shaped fastening elements to the surface of the object or the intended object, fixing a female surface fastener with loop-shaped fastening elements to the surface of the other object, and overlaying the both the surface fasteners on each other to engage the hook-shaped fastening elements with the loop-shaped fastening elements.
A male surface fastener falls roughly into two types: a woven male surface fastener provided with a large number of hook- or mushroom-shaped fastening elements formed from mono-filaments, in which the fastening elements project upword from the surface of a base fabric formed from knitted woven fabric; and a molded male surface fastener provided with a large number of stems formed from plastic, in which the stems project upword from a plastic plate and in which the tip of each of the stems is mushroom- or hook-shaped. The present invention relates to this molded male surface fastener.
As a representative example of such a molded male surface fastener, the surface fastener described in Patent document 1 or a surface fastener with fastening elements being proportionally expanded from those of the surface fastener described in Patent document 1 is known.
When such a surface fastener is attached on the surface, one surface fastener is first fixed to the surface of an object, and the other surface fastener is then fixed to the surface of an intended object. However, before surface fasteners are fastened, the intended object to which a surface fastener has been fixed (or temporarily fastened) is brought close to the surface fastener of the object in the name of temporary fixing or positioning in order to check whether or not an intended object is accurately attached to a predetermined position.
However, in the case of a conventional surface fastener, particularly in the case of a surface fastener with fastening elements being proportionally expanded from those of the surface fastener described in Patent document 1, an unnecessary engagement is caused just by bring both the surface fasteners into contact with each other so that accurate positioning may not be achieved. When caused, such an unnecessary engagement between the surface fasteners needs to be removed to repeat the positioning. On the other hand, if bringing both the surface fasteners close to each other for the positioning of the surface fasteners is omitted in order to avoid the unnecessary engagement being caused and then if the surface fasteners are directly and strongly attached to an appropriate part of the surface of an object and an intended object, respectively, which is so-called permanent engagement, the mispositioning between both the surface fasteners or the mispositioning from a predetermined attachment position of the intended object may be caused. This leads to a difference between the attachment position of the intended object and a predetermined position, resulting in a failure. In this case, when the engagement is released to correct the failure, an intended object might be impaired.
In addition, particularly when the intended object is large, for example, the ceiling material and the wall material of a house, the automotive headliner and the wall member in the luggage room of an automobile, or the like, releasing an unnecessary engagement and repeating the positioning require tremendous time and effort. Furthermore, in a production line running at a constant rate, when a ceiling material and the like have to be attached within a limited time, the production line may be stopped for the release and the positioning. Therefore, it is very important that the positioning need to be conducted promptly and accurately.
To solve such a problem, a strong engagement should be prevented as much as possible from being caused only by overlaying both the surface fasteners on each other in positioning. For this purpose, a method of allowing hook-shaped fastening elements to hardly engage with loop-shaped fastening elements is considered, for example, in which the element densities of the hook-shaped fastening elements and the loop-shaped fastening elements are lowered, in which the shape of the (mushroom cap- or hook-shaped) heads of the hook-shaped fastening elements are downsized, or the like. Using such a method can actually decrease the occurrence of engagement in positioning. However, the engagement force is too low to provide a desired engagement force even after permanent engagement.
In a surface fastener in which loop-shaped fastening elements and hook-shaped fastening elements coexist on the same surface, which is a so-called hook-and-loop coexisting woven surface fastener, Patent document 2 discloses the structure with a reduced engagement being caused in temporary fixing and a strong engagement force being generated after permanent engagement. The technology described in this patent document improves a hook-and-loop coexisting woven surface fastener but cannot be applied to a molded male surface fastener.
Patent document 3 proposes that a molded surface fastener, in which a large number of fastening elements consisting of a stem and an expanded head located on the tip of the stem which projects upword from at least one surface, is provided with a large number of rows of minute projections and depressions and/or a differently leveled rows on the surface of the base material of the molded surface fastener and the surface of the expanded head or the stem of each fastening element so as to improve the gloss of the surface of the surface fastener.
However Patent document 3 does not describe the structure of a molded surface fastener reducing the engagement in temporary fixing and generating a strong engagement force even after permanent engagement.
Patent document 4 proposes a single hook fastener made of an elastic and flexible polymer resin, including a base film layer having an upper principal surface and a lower principal surface in approximately parallel, in which at least 50 spaced hook members per square centimeter project from the upper principal surface of the base, each of the hook members has a height of less than 1000 μm from the upper principal surface and includes a stem added at one end of the base and a head at the end of the stem that is opposed to the base side, and at least the head has a thickness of 50-200 μm in a first direction approximately parallel to the surface of the backing.
However, Patent document 4 does not describe the structure of a molded surface fastener reducing the engagement in temporary fixing and generating a strong engagement force even after permanent engagement.    Patent Document 1: JP 2-5947 A    Patent Document 2: JP 2003-125813 A    Patent Document 3: JP 6-34503 (U)    Patent Document 4: JP 2005-514976 A